WebSVN – HelenOS – Diff – /branches/dd/kernel/generic/src/ipc/ipc.c


/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup genericipc
 * @{
 */
/** @file
 */
 
/* Lock ordering
 *
 * First the answerbox, then the phone.
 */
 
#include <synch/synch.h>
#include <synch/spinlock.h>
#include <synch/mutex.h>
#include <synch/waitq.h>
#include <synch/synch.h>
#include <ipc/ipc.h>
#include <ipc/kbox.h>
#include <ipc/event.h>
#include <errno.h>
#include <mm/slab.h>
#include <arch.h>
#include <proc/task.h>
#include <memstr.h>
#include <debug.h>
 
 
#include <print.h>
#include <console/console.h>
#include <proc/thread.h>
#include <arch/interrupt.h>
#include <ipc/irq.h>
 
/** Open channel that is assigned automatically to new tasks */
answerbox_t *ipc_phone_0 = NULL;
 
static slab_cache_t *ipc_call_slab;
 
/** Initialize a call structure.
 *
 * @param call      Call structure to be initialized.
 */
static void _ipc_call_init(call_t *call)
{
    memsetb(call, sizeof(*call), 0);
    call->callerbox = &TASK->answerbox;
    call->sender = TASK;
    call->buffer = NULL;
}
 
/** Allocate and initialize a call structure.
 *
 * The call is initialized, so that the reply will be directed to
 * TASK->answerbox.
 *
 * @param flags     Parameters for slab_alloc (e.g FRAME_ATOMIC).
 *
 * @return      If flags permit it, return NULL, or initialized kernel
 *          call structure.
 */
call_t *ipc_call_alloc(int flags)
{
    call_t *call;
 
    call = slab_alloc(ipc_call_slab, flags);
    if (call)
        _ipc_call_init(call);
 
    return call;
}
 
/** Initialize a statically allocated call structure.
 *
 * @param call      Statically allocated kernel call structure to be
 *          initialized.
 */
void ipc_call_static_init(call_t *call)
{
    _ipc_call_init(call);
    call->flags |= IPC_CALL_STATIC_ALLOC;
}
 
/** Deallocate a call structure.
 *
 * @param call      Call structure to be freed.
 */
void ipc_call_free(call_t *call)
{
    ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
    /* Check to see if we have data in the IPC_M_DATA_SEND buffer. */
    if (call->buffer)
        free(call->buffer);
    slab_free(ipc_call_slab, call);
}
 
/** Initialize an answerbox structure.
 *
 * @param box       Answerbox structure to be initialized.
 * @param task      Task to which the answerbox belongs.
 */
void ipc_answerbox_init(answerbox_t *box, task_t *task)
{
    spinlock_initialize(&box->lock, "ipc_box_lock");
    spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
    waitq_initialize(&box->wq);
    list_initialize(&box->connected_phones);
    list_initialize(&box->calls);
    list_initialize(&box->dispatched_calls);
    list_initialize(&box->answers);
    list_initialize(&box->irq_notifs);
    list_initialize(&box->irq_head);
    box->task = task;
}
 
/** Connect a phone to an answerbox.
 *
 * @param phone     Initialized phone structure.
 * @param box       Initialized answerbox structure.
 */
void ipc_phone_connect(phone_t *phone, answerbox_t *box)
{
    mutex_lock(&phone->lock);
 
    phone->state = IPC_PHONE_CONNECTED;
    phone->callee = box;
 
    spinlock_lock(&box->lock);
    list_append(&phone->link, &box->connected_phones);
    spinlock_unlock(&box->lock);
 
    mutex_unlock(&phone->lock);
}
 
/** Initialize a phone structure.
 *
 * @param phone     Phone structure to be initialized.
 */
void ipc_phone_init(phone_t *phone)
{
    mutex_initialize(&phone->lock, MUTEX_PASSIVE);
    phone->callee = NULL;
    phone->state = IPC_PHONE_FREE;
    atomic_set(&phone->active_calls, 0);
}
 
/** Helper function to facilitate synchronous calls.
 *
 * @param phone     Destination kernel phone structure.
 * @param request   Call structure with request.
 *
 * @return      EOK on success or EINTR if the sleep was interrupted.
 */
int ipc_call_sync(phone_t *phone, call_t *request)
{
    answerbox_t sync_box;
 
    ipc_answerbox_init(&sync_box, TASK);
 
    /* We will receive data in a special box. */
    request->callerbox = &sync_box;
 
    ipc_call(phone, request);
    if (!ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT,
        SYNCH_FLAGS_INTERRUPTIBLE))
        return EINTR;
    return EOK;
}
 
/** Answer a message which was not dispatched and is not listed in any queue.
 *
 * @param call      Call structure to be answered.
 */
static void _ipc_answer_free_call(call_t *call)
{
    answerbox_t *callerbox = call->callerbox;
 
    call->flags |= IPC_CALL_ANSWERED;
 
    if (call->flags & IPC_CALL_FORWARDED) {
        if (call->caller_phone) {
            /* Demasquerade the caller phone. */
            call->data.phone = call->caller_phone;
        }
    }
 
    spinlock_lock(&callerbox->lock);
    list_append(&call->link, &callerbox->answers);
    spinlock_unlock(&callerbox->lock);
    waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
}
 
/** Answer a message which is in a callee queue.
 *
 * @param box       Answerbox that is answering the message.
 * @param call      Modified request that is being sent back.
 */
void ipc_answer(answerbox_t *box, call_t *call)
{
    /* Remove from active box */
    spinlock_lock(&box->lock);
    list_remove(&call->link);
    spinlock_unlock(&box->lock);
    /* Send back answer */
    _ipc_answer_free_call(call);
}
 
/** Simulate sending back a message.
 *
 * Most errors are better handled by forming a normal backward
 * message and sending it as a normal answer.
 *
 * @param phone     Phone structure the call should appear to come from.
 * @param call      Call structure to be answered.
 * @param err       Return value to be used for the answer.
 */
void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err)
{
    call->data.phone = phone;
    atomic_inc(&phone->active_calls);
    IPC_SET_RETVAL(call->data, err);
    _ipc_answer_free_call(call);
}
 
/** Unsafe unchecking version of ipc_call.
 *
 * @param phone     Phone structure the call comes from.
 * @param box       Destination answerbox structure.
 * @param call      Call structure with request.
 */
static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call)
{
    if (!(call->flags & IPC_CALL_FORWARDED)) {
        atomic_inc(&phone->active_calls);
        call->data.phone = phone;
    }
 
    spinlock_lock(&box->lock);
    list_append(&call->link, &box->calls);
    spinlock_unlock(&box->lock);
    waitq_wakeup(&box->wq, WAKEUP_FIRST);
}
 
/** Send an asynchronous request using a phone to an answerbox.
 *
 * @param phone     Phone structure the call comes from and which is
 *          connected to the destination answerbox.
 * @param call      Call structure with request.
 *
 * @return      Return 0 on success, ENOENT on error.
 */
int ipc_call(phone_t *phone, call_t *call)
{
    answerbox_t *box;
 
    mutex_lock(&phone->lock);
    if (phone->state != IPC_PHONE_CONNECTED) {
        mutex_unlock(&phone->lock);
        if (call->flags & IPC_CALL_FORWARDED) {
            IPC_SET_RETVAL(call->data, EFORWARD);
            _ipc_answer_free_call(call);
        } else {
            if (phone->state == IPC_PHONE_HUNGUP)
                ipc_backsend_err(phone, call, EHANGUP);
            else
                ipc_backsend_err(phone, call, ENOENT);
        }
        return ENOENT;
    }
    box = phone->callee;
    _ipc_call(phone, box, call);
   
    mutex_unlock(&phone->lock);
    return 0;
}
 
/** Disconnect phone from answerbox.
 *
 * This call leaves the phone in the HUNGUP state. The change to 'free' is done
 * lazily later.
 *
 * @param phone     Phone structure to be hung up.
 *              
 * @return      Return 0 if the phone is disconnected.
 *          Return -1 if the phone was already disconnected.
 */
int ipc_phone_hangup(phone_t *phone)
{
    answerbox_t *box;
    call_t *call;
   
    mutex_lock(&phone->lock);
    if (phone->state == IPC_PHONE_FREE ||
        phone->state == IPC_PHONE_HUNGUP ||
        phone->state == IPC_PHONE_CONNECTING) {
        mutex_unlock(&phone->lock);
        return -1;
    }
    box = phone->callee;
    if (phone->state != IPC_PHONE_SLAMMED) {
        /* Remove myself from answerbox */
        spinlock_lock(&box->lock);
        list_remove(&phone->link);
        spinlock_unlock(&box->lock);
 
        if (phone->state != IPC_PHONE_SLAMMED) {
            call = ipc_call_alloc(0);
            IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
            call->flags |= IPC_CALL_DISCARD_ANSWER;
            _ipc_call(phone, box, call);
        }
    }
 
    phone->state = IPC_PHONE_HUNGUP;
    mutex_unlock(&phone->lock);
 
    return 0;
}
 
/** Forwards call from one answerbox to another one.
 *
 * @param call      Call structure to be redirected.
 * @param newphone  Phone structure to target answerbox.
 * @param oldbox    Old answerbox structure.
 * @param mode      Flags that specify mode of the forward operation.
 *
 * @return      Return 0 if forwarding succeeded or an error code if
 *          there was error.
 *
 * The return value serves only as an information for the forwarder,
 * the original caller is notified automatically with EFORWARD.
 */
int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox, int mode)
{
    spinlock_lock(&oldbox->lock);
    list_remove(&call->link);
    spinlock_unlock(&oldbox->lock);
 
    if (mode & IPC_FF_ROUTE_FROM_ME) {
        if (!call->caller_phone)
            call->caller_phone = call->data.phone;
        call->data.phone = newphone;
    }
 
    return ipc_call(newphone, call);
}
 
 
/** Wait for a phone call.
 *
 * @param box       Answerbox expecting the call.
 * @param usec      Timeout in microseconds. See documentation for
 *          waitq_sleep_timeout() for decription of its special
 *          meaning.
 * @param flags     Select mode of sleep operation. See documentation for
 *          waitq_sleep_timeout() for description of its special
 *          meaning.
 * @return      Recived call structure or NULL.
 *
 * To distinguish between a call and an answer, have a look at call->flags.
 */
call_t *ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags)
{
    call_t *request;
    ipl_t ipl;
    int rc;
 
restart:
    rc = waitq_sleep_timeout(&box->wq, usec, flags);
    if (SYNCH_FAILED(rc))
        return NULL;
   
    spinlock_lock(&box->lock);
    if (!list_empty(&box->irq_notifs)) {
        ipl = interrupts_disable();
        spinlock_lock(&box->irq_lock);
 
        request = list_get_instance(box->irq_notifs.next, call_t, link);
        list_remove(&request->link);
 
        spinlock_unlock(&box->irq_lock);
        interrupts_restore(ipl);
    } else if (!list_empty(&box->answers)) {
        /* Handle asynchronous answers */
        request = list_get_instance(box->answers.next, call_t, link);
        list_remove(&request->link);
        atomic_dec(&request->data.phone->active_calls);
    } else if (!list_empty(&box->calls)) {
        /* Handle requests */
        request = list_get_instance(box->calls.next, call_t, link);
        list_remove(&request->link);
        /* Append request to dispatch queue */
        list_append(&request->link, &box->dispatched_calls);
    } else {
        /* This can happen regularly after ipc_cleanup */
        spinlock_unlock(&box->lock);
        goto restart;
    }
    spinlock_unlock(&box->lock);
    return request;
}
 
/** Answer all calls from list with EHANGUP answer.
 *
 * @param lst       Head of the list to be cleaned up.
 */
void ipc_cleanup_call_list(link_t *lst)
{
    call_t *call;
 
    while (!list_empty(lst)) {
        call = list_get_instance(lst->next, call_t, link);
        if (call->buffer)
            free(call->buffer);
        list_remove(&call->link);
 
        IPC_SET_RETVAL(call->data, EHANGUP);
        _ipc_answer_free_call(call);
    }
}
 
/** Disconnects all phones connected to an answerbox.
 *
 * @param box       Answerbox to disconnect phones from.
 * @param notify_box    If true, the answerbox will get a hangup message for
 *          each disconnected phone.
 */
void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)
{
    phone_t *phone;
    DEADLOCK_PROBE_INIT(p_phonelck);
    ipl_t ipl;
    call_t *call;
 
    call = notify_box ? ipc_call_alloc(0) : NULL;
 
    /* Disconnect all phones connected to our answerbox */
restart_phones:
    ipl = interrupts_disable();
    spinlock_lock(&box->lock);
    while (!list_empty(&box->connected_phones)) {
        phone = list_get_instance(box->connected_phones.next,
            phone_t, link);
        if (SYNCH_FAILED(mutex_trylock(&phone->lock))) {
            spinlock_unlock(&box->lock);
            interrupts_restore(ipl);
            DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
            goto restart_phones;
        }
       
        /* Disconnect phone */
        ASSERT(phone->state == IPC_PHONE_CONNECTED);
 
        list_remove(&phone->link);
        phone->state = IPC_PHONE_SLAMMED;
 
        if (notify_box) {
            mutex_unlock(&phone->lock);
            spinlock_unlock(&box->lock);
            interrupts_restore(ipl);
 
            /*
             * Send one message to the answerbox for each
             * phone. Used to make sure the kbox thread
             * wakes up after the last phone has been
             * disconnected.
             */
            IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
            call->flags |= IPC_CALL_DISCARD_ANSWER;
            _ipc_call(phone, box, call);
 
            /* Allocate another call in advance */
            call = ipc_call_alloc(0);
 
            /* Must start again */
            goto restart_phones;
        }
 
        mutex_unlock(&phone->lock);
    }
 
    spinlock_unlock(&box->lock);
    interrupts_restore(ipl);
 
    /* Free unused call */
    if (call)
        ipc_call_free(call);
}
 
/** Cleans up all IPC communication of the current task.
 *
 * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you
 * have to change it as well if you want to cleanup other tasks than TASK.
 */
void ipc_cleanup(void)
{
    int i;
    call_t *call;
 
    /* Disconnect all our phones ('ipc_phone_hangup') */
    for (i = 0; i < IPC_MAX_PHONES; i++)
        ipc_phone_hangup(&TASK->phones[i]);
 
    /* Unsubscribe from any event notifications. */
    event_cleanup_answerbox(&TASK->answerbox);
 
    /* Disconnect all connected irqs */
    ipc_irq_cleanup(&TASK->answerbox);
 
    /* Disconnect all phones connected to our regular answerbox */
    ipc_answerbox_slam_phones(&TASK->answerbox, false);
 
#ifdef CONFIG_UDEBUG
    /* Clean up kbox thread and communications */
    ipc_kbox_cleanup();
#endif
 
    /* Answer all messages in 'calls' and 'dispatched_calls' queues */
    spinlock_lock(&TASK->answerbox.lock);
    ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls);
    ipc_cleanup_call_list(&TASK->answerbox.calls);
    spinlock_unlock(&TASK->answerbox.lock);
   
    /* Wait for all async answers to arrive */
    while (1) {
        /* Go through all phones, until all are FREE... */
        /* Locking not needed, no one else should modify
         * it, when we are in cleanup */
        for (i = 0; i < IPC_MAX_PHONES; i++) {
            if (TASK->phones[i].state == IPC_PHONE_HUNGUP &&
                atomic_get(&TASK->phones[i].active_calls) == 0)
                TASK->phones[i].state = IPC_PHONE_FREE;
           
            /* Just for sure, we might have had some
             * IPC_PHONE_CONNECTING phones */
            if (TASK->phones[i].state == IPC_PHONE_CONNECTED)
                ipc_phone_hangup(&TASK->phones[i]);
            /* If the hangup succeeded, it has sent a HANGUP
             * message, the IPC is now in HUNGUP state, we
             * wait for the reply to come */
           
            if (TASK->phones[i].state != IPC_PHONE_FREE)
                break;
        }
        /* Voila, got into cleanup */
        if (i == IPC_MAX_PHONES)
            break;
       
        call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT,
            SYNCH_FLAGS_NONE);
        ASSERT((call->flags & IPC_CALL_ANSWERED) ||
            (call->flags & IPC_CALL_NOTIF));
        ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
       
        /*
         * Record the receipt of this call in the current task's counter
         * of active calls. IPC_M_PHONE_HUNGUP calls do not contribute
         * to this counter so do not record answers to them either.
         */
        if (!(call->flags & IPC_CALL_DISCARD_ANSWER))
            atomic_dec(&TASK->active_calls);
        ipc_call_free(call);
    }
}
 
 
/** Initilize IPC subsystem */
void ipc_init(void)
{
    ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL,
        NULL, 0);
}
 
 
/** List answerbox contents.
 *
 * @param taskid    Task ID.
 */
void ipc_print_task(task_id_t taskid)
{
    task_t *task;
    int i;
    call_t *call;
    link_t *tmp;
   
    spinlock_lock(&tasks_lock);
    task = task_find_by_id(taskid);
    if (task)
        spinlock_lock(&task->lock);
    spinlock_unlock(&tasks_lock);
    if (!task)
        return;
 
    /* Print opened phones & details */
    printf("PHONE:\n");
    for (i = 0; i < IPC_MAX_PHONES; i++) {
        if (SYNCH_FAILED(mutex_trylock(&task->phones[i].lock))) {
            printf("%d: mutex busy\n", i);
            continue;
        }
        if (task->phones[i].state != IPC_PHONE_FREE) {
            printf("%d: ", i);
            switch (task->phones[i].state) {
            case IPC_PHONE_CONNECTING:
                printf("connecting ");
                break;
            case IPC_PHONE_CONNECTED:
                printf("connected to: %p ",
                       task->phones[i].callee);
                break;
            case IPC_PHONE_SLAMMED:
                printf("slammed by: %p ",
                       task->phones[i].callee);
                break;
            case IPC_PHONE_HUNGUP:
                printf("hung up - was: %p ",
                       task->phones[i].callee);
                break;
            default:
                break;
            }
            printf("active: %ld\n",
                atomic_get(&task->phones[i].active_calls));
        }
        mutex_unlock(&task->phones[i].lock);
    }
 
 
    /* Print answerbox - calls */
    spinlock_lock(&task->answerbox.lock);
    printf("ABOX - CALLS:\n");
    for (tmp = task->answerbox.calls.next; tmp != &task->answerbox.calls;
        tmp = tmp->next) {
        call = list_get_instance(tmp, call_t, link);
        printf("Callid: %p Srctask:%" PRIu64 " M:%" PRIun
            " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun
            " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call,
            call->sender->taskid,
            IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
            IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
            IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
            call->flags);
    }
    /* Print answerbox - calls */
    printf("ABOX - DISPATCHED CALLS:\n");
    for (tmp = task->answerbox.dispatched_calls.next;
        tmp != &task->answerbox.dispatched_calls;
        tmp = tmp->next) {
        call = list_get_instance(tmp, call_t, link);
        printf("Callid: %p Srctask:%" PRIu64 " M:%" PRIun
            " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun
            " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call,
            call->sender->taskid,
            IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
            IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
            IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
            call->flags);
    }
    /* Print answerbox - calls */
    printf("ABOX - ANSWERS:\n");
    for (tmp = task->answerbox.answers.next;
        tmp != &task->answerbox.answers;
        tmp = tmp->next) {
        call = list_get_instance(tmp, call_t, link);
        printf("Callid:%p M:%" PRIun " A1:%" PRIun " A2:%" PRIun
            " A3:%" PRIun " A4:%" PRIun " A5:%" PRIun " Flags:%x\n",
            call, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data),
            IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data),
            IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data),
            call->flags);
    }
 
    spinlock_unlock(&task->answerbox.lock);
    spinlock_unlock(&task->lock);
}
 
/** @}
 */
 

Rev 4201	Rev 4296
1	/*	1	/*
2	* Copyright (c) 2006 Ondrej Palkovsky	2	* Copyright (c) 2006 Ondrej Palkovsky
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup genericipc	29	/** @addtogroup genericipc
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	*/	33	*/
34		34
35	/* Lock ordering	35	/* Lock ordering
36	*	36	*
37	* First the answerbox, then the phone.	37	* First the answerbox, then the phone.
38	*/	38	*/
39		39
40	#include <synch/synch.h>	40	#include <synch/synch.h>
41	#include <synch/spinlock.h>	41	#include <synch/spinlock.h>
42	#include <synch/mutex.h>	42	#include <synch/mutex.h>
43	#include <synch/waitq.h>	43	#include <synch/waitq.h>
44	#include <synch/synch.h>	44	#include <synch/synch.h>
45	#include <ipc/ipc.h>	45	#include <ipc/ipc.h>
46	#include <ipc/kbox.h>	46	#include <ipc/kbox.h>
47	#include <event/event.h>	47	#include <ipc/event.h>
48	#include <errno.h>	48	#include <errno.h>
49	#include <mm/slab.h>	49	#include <mm/slab.h>
50	#include <arch.h>	50	#include <arch.h>
51	#include <proc/task.h>	51	#include <proc/task.h>
52	#include <memstr.h>	52	#include <memstr.h>
53	#include <debug.h>	53	#include <debug.h>
54		-
55		-
56	#include <print.h>	54	#include <print.h>
57	#include <console/console.h>	55	#include <console/console.h>
58	#include <proc/thread.h>	56	#include <proc/thread.h>
59	#include <arch/interrupt.h>	57	#include <arch/interrupt.h>
60	#include <ipc/irq.h>	58	#include <ipc/irq.h>
61		59
62	/** Open channel that is assigned automatically to new tasks */	60	/** Open channel that is assigned automatically to new tasks */
63	answerbox_t *ipc_phone_0 = NULL;	61	answerbox_t *ipc_phone_0 = NULL;
64		62
65	static slab_cache_t *ipc_call_slab;	63	static slab_cache_t *ipc_call_slab;
66		64
67	/** Initialize a call structure.	65	/** Initialize a call structure.
68	*	66	*
69	* @param call Call structure to be initialized.	67	* @param call Call structure to be initialized.
70	*/	68	*/
71	static void _ipc_call_init(call_t *call)	69	static void _ipc_call_init(call_t *call)
72	{	70	{
73	memsetb(call, sizeof(*call), 0);	71	memsetb(call, sizeof(*call), 0);
74	call->callerbox = &TASK->answerbox;	72	call->callerbox = &TASK->answerbox;
75	call->sender = TASK;	73	call->sender = TASK;
76	call->buffer = NULL;	74	call->buffer = NULL;
77	}	75	}
78		76
79	/** Allocate and initialize a call structure.	77	/** Allocate and initialize a call structure.
80	*	78	*
81	* The call is initialized, so that the reply will be directed to	79	* The call is initialized, so that the reply will be directed to
82	* TASK->answerbox.	80	* TASK->answerbox.
83	*	81	*
84	* @param flags Parameters for slab_alloc (e.g FRAME_ATOMIC).	82	* @param flags Parameters for slab_alloc (e.g FRAME_ATOMIC).
85	*	83	*
86	* @return If flags permit it, return NULL, or initialized kernel	84	* @return If flags permit it, return NULL, or initialized kernel
87	* call structure.	85	* call structure.
88	*/	86	*/
89	call_t *ipc_call_alloc(int flags)	87	call_t *ipc_call_alloc(int flags)
90	{	88	{
91	call_t *call;	89	call_t *call;
92		90
93	call = slab_alloc(ipc_call_slab, flags);	91	call = slab_alloc(ipc_call_slab, flags);
94	if (call)	92	if (call)
95	_ipc_call_init(call);	93	_ipc_call_init(call);
96		94
97	return call;	95	return call;
98	}	96	}
99		97
100	/** Initialize a statically allocated call structure.	98	/** Initialize a statically allocated call structure.
101	*	99	*
102	* @param call Statically allocated kernel call structure to be	100	* @param call Statically allocated kernel call structure to be
103	* initialized.	101	* initialized.
104	*/	102	*/
105	void ipc_call_static_init(call_t *call)	103	void ipc_call_static_init(call_t *call)
106	{	104	{
107	_ipc_call_init(call);	105	_ipc_call_init(call);
108	call->flags \|= IPC_CALL_STATIC_ALLOC;	106	call->flags \|= IPC_CALL_STATIC_ALLOC;
109	}	107	}
110		108
111	/** Deallocate a call structure.	109	/** Deallocate a call structure.
112	*	110	*
113	* @param call Call structure to be freed.	111	* @param call Call structure to be freed.
114	*/	112	*/
115	void ipc_call_free(call_t *call)	113	void ipc_call_free(call_t *call)
116	{	114	{
117	ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));	115	ASSERT(!(call->flags & IPC_CALL_STATIC_ALLOC));
118	/* Check to see if we have data in the IPC_M_DATA_SEND buffer. */	116	/* Check to see if we have data in the IPC_M_DATA_SEND buffer. */
119	if (call->buffer)	117	if (call->buffer)
120	free(call->buffer);	118	free(call->buffer);
121	slab_free(ipc_call_slab, call);	119	slab_free(ipc_call_slab, call);
122	}	120	}
123		121
124	/** Initialize an answerbox structure.	122	/** Initialize an answerbox structure.
125	*	123	*
126	* @param box Answerbox structure to be initialized.	124	* @param box Answerbox structure to be initialized.
127	* @param task Task to which the answerbox belongs.	125	* @param task Task to which the answerbox belongs.
128	*/	126	*/
129	void ipc_answerbox_init(answerbox_t box, task_t task)	127	void ipc_answerbox_init(answerbox_t box, task_t task)
130	{	128	{
131	spinlock_initialize(&box->lock, "ipc_box_lock");	129	spinlock_initialize(&box->lock, "ipc_box_lock");
132	spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");	130	spinlock_initialize(&box->irq_lock, "ipc_box_irqlock");
133	waitq_initialize(&box->wq);	131	waitq_initialize(&box->wq);
134	list_initialize(&box->connected_phones);	132	list_initialize(&box->connected_phones);
135	list_initialize(&box->calls);	133	list_initialize(&box->calls);
136	list_initialize(&box->dispatched_calls);	134	list_initialize(&box->dispatched_calls);
137	list_initialize(&box->answers);	135	list_initialize(&box->answers);
138	list_initialize(&box->irq_notifs);	136	list_initialize(&box->irq_notifs);
139	list_initialize(&box->irq_head);	137	list_initialize(&box->irq_head);
140	box->task = task;	138	box->task = task;
141	}	139	}
142		140
143	/** Connect a phone to an answerbox.	141	/** Connect a phone to an answerbox.
144	*	142	*
145	* @param phone Initialized phone structure.	143	* @param phone Initialized phone structure.
146	* @param box Initialized answerbox structure.	144	* @param box Initialized answerbox structure.
147	*/	145	*/
148	void ipc_phone_connect(phone_t phone, answerbox_t box)	146	void ipc_phone_connect(phone_t phone, answerbox_t box)
149	{	147	{
150	mutex_lock(&phone->lock);	148	mutex_lock(&phone->lock);
151		149
152	phone->state = IPC_PHONE_CONNECTED;	150	phone->state = IPC_PHONE_CONNECTED;
153	phone->callee = box;	151	phone->callee = box;
154		152
155	spinlock_lock(&box->lock);	153	spinlock_lock(&box->lock);
156	list_append(&phone->link, &box->connected_phones);	154	list_append(&phone->link, &box->connected_phones);
157	spinlock_unlock(&box->lock);	155	spinlock_unlock(&box->lock);
158		156
159	mutex_unlock(&phone->lock);	157	mutex_unlock(&phone->lock);
160	}	158	}
161		159
162	/** Initialize a phone structure.	160	/** Initialize a phone structure.
163	*	161	*
164	* @param phone Phone structure to be initialized.	162	* @param phone Phone structure to be initialized.
165	*/	163	*/
166	void ipc_phone_init(phone_t *phone)	164	void ipc_phone_init(phone_t *phone)
167	{	165	{
168	mutex_initialize(&phone->lock, MUTEX_PASSIVE);	166	mutex_initialize(&phone->lock, MUTEX_PASSIVE);
169	phone->callee = NULL;	167	phone->callee = NULL;
170	phone->state = IPC_PHONE_FREE;	168	phone->state = IPC_PHONE_FREE;
171	atomic_set(&phone->active_calls, 0);	169	atomic_set(&phone->active_calls, 0);
172	}	170	}
173		171
174	/** Helper function to facilitate synchronous calls.	172	/** Helper function to facilitate synchronous calls.
175	*	173	*
176	* @param phone Destination kernel phone structure.	174	* @param phone Destination kernel phone structure.
177	* @param request Call structure with request.	175	* @param request Call structure with request.
178	*	176	*
179	* @return EOK on success or EINTR if the sleep was interrupted.	177	* @return EOK on success or EINTR if the sleep was interrupted.
180	*/	178	*/
181	int ipc_call_sync(phone_t phone, call_t request)	179	int ipc_call_sync(phone_t phone, call_t request)
182	{	180	{
183	answerbox_t sync_box;	181	answerbox_t sync_box;
184		182
185	ipc_answerbox_init(&sync_box, TASK);	183	ipc_answerbox_init(&sync_box, TASK);
186		184
187	/* We will receive data in a special box. */	185	/* We will receive data in a special box. */
188	request->callerbox = &sync_box;	186	request->callerbox = &sync_box;
189		187
190	ipc_call(phone, request);	188	ipc_call(phone, request);
191	if (!ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT,	189	if (!ipc_wait_for_call(&sync_box, SYNCH_NO_TIMEOUT,
192	SYNCH_FLAGS_INTERRUPTIBLE))	190	SYNCH_FLAGS_INTERRUPTIBLE))
193	return EINTR;	191	return EINTR;
194	return EOK;	192	return EOK;
195	}	193	}
196		194
197	/** Answer a message which was not dispatched and is not listed in any queue.	195	/** Answer a message which was not dispatched and is not listed in any queue.
198	*	196	*
199	* @param call Call structure to be answered.	197	* @param call Call structure to be answered.
200	*/	198	*/
201	static void _ipc_answer_free_call(call_t *call)	199	static void _ipc_answer_free_call(call_t *call)
202	{	200	{
203	answerbox_t *callerbox = call->callerbox;	201	answerbox_t *callerbox = call->callerbox;
204		202
205	call->flags \|= IPC_CALL_ANSWERED;	203	call->flags \|= IPC_CALL_ANSWERED;
206		204
207	if (call->flags & IPC_CALL_FORWARDED) {	205	if (call->flags & IPC_CALL_FORWARDED) {
208	if (call->caller_phone) {	206	if (call->caller_phone) {
209	/* Demasquerade the caller phone. */	207	/* Demasquerade the caller phone. */
210	call->data.phone = call->caller_phone;	208	call->data.phone = call->caller_phone;
211	}	209	}
212	}	210	}
213		211
214	spinlock_lock(&callerbox->lock);	212	spinlock_lock(&callerbox->lock);
215	list_append(&call->link, &callerbox->answers);	213	list_append(&call->link, &callerbox->answers);
216	spinlock_unlock(&callerbox->lock);	214	spinlock_unlock(&callerbox->lock);
217	waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);	215	waitq_wakeup(&callerbox->wq, WAKEUP_FIRST);
218	}	216	}
219		217
220	/** Answer a message which is in a callee queue.	218	/** Answer a message which is in a callee queue.
221	*	219	*
222	* @param box Answerbox that is answering the message.	220	* @param box Answerbox that is answering the message.
223	* @param call Modified request that is being sent back.	221	* @param call Modified request that is being sent back.
224	*/	222	*/
225	void ipc_answer(answerbox_t box, call_t call)	223	void ipc_answer(answerbox_t box, call_t call)
226	{	224	{
227	/* Remove from active box */	225	/* Remove from active box */
228	spinlock_lock(&box->lock);	226	spinlock_lock(&box->lock);
229	list_remove(&call->link);	227	list_remove(&call->link);
230	spinlock_unlock(&box->lock);	228	spinlock_unlock(&box->lock);
231	/* Send back answer */	229	/* Send back answer */
232	_ipc_answer_free_call(call);	230	_ipc_answer_free_call(call);
233	}	231	}
234		232
235	/** Simulate sending back a message.	233	/** Simulate sending back a message.
236	*	234	*
237	* Most errors are better handled by forming a normal backward	235	* Most errors are better handled by forming a normal backward
238	* message and sending it as a normal answer.	236	* message and sending it as a normal answer.
239	*	237	*
240	* @param phone Phone structure the call should appear to come from.	238	* @param phone Phone structure the call should appear to come from.
241	* @param call Call structure to be answered.	239	* @param call Call structure to be answered.
242	* @param err Return value to be used for the answer.	240	* @param err Return value to be used for the answer.
243	*/	241	*/
244	void ipc_backsend_err(phone_t phone, call_t call, unative_t err)	242	void ipc_backsend_err(phone_t phone, call_t call, unative_t err)
245	{	243	{
246	call->data.phone = phone;	244	call->data.phone = phone;
247	atomic_inc(&phone->active_calls);	245	atomic_inc(&phone->active_calls);
248	IPC_SET_RETVAL(call->data, err);	246	IPC_SET_RETVAL(call->data, err);
249	_ipc_answer_free_call(call);	247	_ipc_answer_free_call(call);
250	}	248	}
251		249
252	/** Unsafe unchecking version of ipc_call.	250	/** Unsafe unchecking version of ipc_call.
253	*	251	*
254	* @param phone Phone structure the call comes from.	252	* @param phone Phone structure the call comes from.
255	* @param box Destination answerbox structure.	253	* @param box Destination answerbox structure.
256	* @param call Call structure with request.	254	* @param call Call structure with request.
257	*/	255	*/
258	static void _ipc_call(phone_t phone, answerbox_t box, call_t *call)	256	static void _ipc_call(phone_t phone, answerbox_t box, call_t *call)
259	{	257	{
260	if (!(call->flags & IPC_CALL_FORWARDED)) {	258	if (!(call->flags & IPC_CALL_FORWARDED)) {
261	atomic_inc(&phone->active_calls);	259	atomic_inc(&phone->active_calls);
262	call->data.phone = phone;	260	call->data.phone = phone;
263	}	261	}
264		262
265	spinlock_lock(&box->lock);	263	spinlock_lock(&box->lock);
266	list_append(&call->link, &box->calls);	264	list_append(&call->link, &box->calls);
267	spinlock_unlock(&box->lock);	265	spinlock_unlock(&box->lock);
268	waitq_wakeup(&box->wq, WAKEUP_FIRST);	266	waitq_wakeup(&box->wq, WAKEUP_FIRST);
269	}	267	}
270		268
271	/** Send an asynchronous request using a phone to an answerbox.	269	/** Send an asynchronous request using a phone to an answerbox.
272	*	270	*
273	* @param phone Phone structure the call comes from and which is	271	* @param phone Phone structure the call comes from and which is
274	* connected to the destination answerbox.	272	* connected to the destination answerbox.
275	* @param call Call structure with request.	273	* @param call Call structure with request.
276	*	274	*
277	* @return Return 0 on success, ENOENT on error.	275	* @return Return 0 on success, ENOENT on error.
278	*/	276	*/
279	int ipc_call(phone_t phone, call_t call)	277	int ipc_call(phone_t phone, call_t call)
280	{	278	{
281	answerbox_t *box;	279	answerbox_t *box;
282		280
283	mutex_lock(&phone->lock);	281	mutex_lock(&phone->lock);
284	if (phone->state != IPC_PHONE_CONNECTED) {	282	if (phone->state != IPC_PHONE_CONNECTED) {
285	mutex_unlock(&phone->lock);	283	mutex_unlock(&phone->lock);
286	if (call->flags & IPC_CALL_FORWARDED) {	284	if (call->flags & IPC_CALL_FORWARDED) {
287	IPC_SET_RETVAL(call->data, EFORWARD);	285	IPC_SET_RETVAL(call->data, EFORWARD);
288	_ipc_answer_free_call(call);	286	_ipc_answer_free_call(call);
289	} else {	287	} else {
290	if (phone->state == IPC_PHONE_HUNGUP)	288	if (phone->state == IPC_PHONE_HUNGUP)
291	ipc_backsend_err(phone, call, EHANGUP);	289	ipc_backsend_err(phone, call, EHANGUP);
292	else	290	else
293	ipc_backsend_err(phone, call, ENOENT);	291	ipc_backsend_err(phone, call, ENOENT);
294	}	292	}
295	return ENOENT;	293	return ENOENT;
296	}	294	}
297	box = phone->callee;	295	box = phone->callee;
298	_ipc_call(phone, box, call);	296	_ipc_call(phone, box, call);
299		297
300	mutex_unlock(&phone->lock);	298	mutex_unlock(&phone->lock);
301	return 0;	299	return 0;
302	}	300	}
303		301
304	/** Disconnect phone from answerbox.	302	/** Disconnect phone from answerbox.
305	*	303	*
306	* This call leaves the phone in the HUNGUP state. The change to 'free' is done	304	* This call leaves the phone in the HUNGUP state. The change to 'free' is done
307	* lazily later.	305	* lazily later.
308	*	306	*
309	* @param phone Phone structure to be hung up.	307	* @param phone Phone structure to be hung up.
310	*	308	*
311	* @return Return 0 if the phone is disconnected.	309	* @return Return 0 if the phone is disconnected.
312	* Return -1 if the phone was already disconnected.	310	* Return -1 if the phone was already disconnected.
313	*/	311	*/
314	int ipc_phone_hangup(phone_t *phone)	312	int ipc_phone_hangup(phone_t *phone)
315	{	313	{
316	answerbox_t *box;	314	answerbox_t *box;
317	call_t *call;	315	call_t *call;
318		316
319	mutex_lock(&phone->lock);	317	mutex_lock(&phone->lock);
320	if (phone->state == IPC_PHONE_FREE \|\|	318	if (phone->state == IPC_PHONE_FREE \|\|
321	phone->state == IPC_PHONE_HUNGUP \|\|	319	phone->state == IPC_PHONE_HUNGUP \|\|
322	phone->state == IPC_PHONE_CONNECTING) {	320	phone->state == IPC_PHONE_CONNECTING) {
323	mutex_unlock(&phone->lock);	321	mutex_unlock(&phone->lock);
324	return -1;	322	return -1;
325	}	323	}
326	box = phone->callee;	324	box = phone->callee;
327	if (phone->state != IPC_PHONE_SLAMMED) {	325	if (phone->state != IPC_PHONE_SLAMMED) {
328	/* Remove myself from answerbox */	326	/* Remove myself from answerbox */
329	spinlock_lock(&box->lock);	327	spinlock_lock(&box->lock);
330	list_remove(&phone->link);	328	list_remove(&phone->link);
331	spinlock_unlock(&box->lock);	329	spinlock_unlock(&box->lock);
332		330
333	if (phone->state != IPC_PHONE_SLAMMED) {	331	if (phone->state != IPC_PHONE_SLAMMED) {
334	call = ipc_call_alloc(0);	332	call = ipc_call_alloc(0);
335	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);	333	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
336	call->flags \|= IPC_CALL_DISCARD_ANSWER;	334	call->flags \|= IPC_CALL_DISCARD_ANSWER;
337	_ipc_call(phone, box, call);	335	_ipc_call(phone, box, call);
338	}	336	}
339	}	337	}
340		338
341	phone->state = IPC_PHONE_HUNGUP;	339	phone->state = IPC_PHONE_HUNGUP;
342	mutex_unlock(&phone->lock);	340	mutex_unlock(&phone->lock);
343		341
344	return 0;	342	return 0;
345	}	343	}
346		344
347	/** Forwards call from one answerbox to another one.	345	/** Forwards call from one answerbox to another one.
348	*	346	*
349	* @param call Call structure to be redirected.	347	* @param call Call structure to be redirected.
350	* @param newphone Phone structure to target answerbox.	348	* @param newphone Phone structure to target answerbox.
351	* @param oldbox Old answerbox structure.	349	* @param oldbox Old answerbox structure.
352	* @param mode Flags that specify mode of the forward operation.	350	* @param mode Flags that specify mode of the forward operation.
353	*	351	*
354	* @return Return 0 if forwarding succeeded or an error code if	352	* @return Return 0 if forwarding succeeded or an error code if
355	* there was error.	353	* there was error.
356	*	354	*
357	* The return value serves only as an information for the forwarder,	355	* The return value serves only as an information for the forwarder,
358	* the original caller is notified automatically with EFORWARD.	356	* the original caller is notified automatically with EFORWARD.
359	*/	357	*/
360	int ipc_forward(call_t call, phone_t newphone, answerbox_t *oldbox, int mode)	358	int ipc_forward(call_t call, phone_t newphone, answerbox_t *oldbox, int mode)
361	{	359	{
362	spinlock_lock(&oldbox->lock);	360	spinlock_lock(&oldbox->lock);
363	list_remove(&call->link);	361	list_remove(&call->link);
364	spinlock_unlock(&oldbox->lock);	362	spinlock_unlock(&oldbox->lock);
365		363
366	if (mode & IPC_FF_ROUTE_FROM_ME) {	364	if (mode & IPC_FF_ROUTE_FROM_ME) {
367	if (!call->caller_phone)	365	if (!call->caller_phone)
368	call->caller_phone = call->data.phone;	366	call->caller_phone = call->data.phone;
369	call->data.phone = newphone;	367	call->data.phone = newphone;
370	}	368	}
371		369
372	return ipc_call(newphone, call);	370	return ipc_call(newphone, call);
373	}	371	}
374		372
375		373
376	/** Wait for a phone call.	374	/** Wait for a phone call.
377	*	375	*
378	* @param box Answerbox expecting the call.	376	* @param box Answerbox expecting the call.
379	* @param usec Timeout in microseconds. See documentation for	377	* @param usec Timeout in microseconds. See documentation for
380	* waitq_sleep_timeout() for decription of its special	378	* waitq_sleep_timeout() for decription of its special
381	* meaning.	379	* meaning.
382	* @param flags Select mode of sleep operation. See documentation for	380	* @param flags Select mode of sleep operation. See documentation for
383	* waitq_sleep_timeout() for description of its special	381	* waitq_sleep_timeout() for description of its special
384	* meaning.	382	* meaning.
385	* @return Recived call structure or NULL.	383	* @return Recived call structure or NULL.
386	*	384	*
387	* To distinguish between a call and an answer, have a look at call->flags.	385	* To distinguish between a call and an answer, have a look at call->flags.
388	*/	386	*/
389	call_t ipc_wait_for_call(answerbox_t box, uint32_t usec, int flags)	387	call_t ipc_wait_for_call(answerbox_t box, uint32_t usec, int flags)
390	{	388	{
391	call_t *request;	389	call_t *request;
392	ipl_t ipl;	390	ipl_t ipl;
393	int rc;	391	int rc;
394		392
395	restart:	393	restart:
396	rc = waitq_sleep_timeout(&box->wq, usec, flags);	394	rc = waitq_sleep_timeout(&box->wq, usec, flags);
397	if (SYNCH_FAILED(rc))	395	if (SYNCH_FAILED(rc))
398	return NULL;	396	return NULL;
399		397
400	spinlock_lock(&box->lock);	398	spinlock_lock(&box->lock);
401	if (!list_empty(&box->irq_notifs)) {	399	if (!list_empty(&box->irq_notifs)) {
402	ipl = interrupts_disable();	400	ipl = interrupts_disable();
403	spinlock_lock(&box->irq_lock);	401	spinlock_lock(&box->irq_lock);
404		402
405	request = list_get_instance(box->irq_notifs.next, call_t, link);	403	request = list_get_instance(box->irq_notifs.next, call_t, link);
406	list_remove(&request->link);	404	list_remove(&request->link);
407		405
408	spinlock_unlock(&box->irq_lock);	406	spinlock_unlock(&box->irq_lock);
409	interrupts_restore(ipl);	407	interrupts_restore(ipl);
410	} else if (!list_empty(&box->answers)) {	408	} else if (!list_empty(&box->answers)) {
411	/* Handle asynchronous answers */	409	/* Handle asynchronous answers */
412	request = list_get_instance(box->answers.next, call_t, link);	410	request = list_get_instance(box->answers.next, call_t, link);
413	list_remove(&request->link);	411	list_remove(&request->link);
414	atomic_dec(&request->data.phone->active_calls);	412	atomic_dec(&request->data.phone->active_calls);
415	} else if (!list_empty(&box->calls)) {	413	} else if (!list_empty(&box->calls)) {
416	/* Handle requests */	414	/* Handle requests */
417	request = list_get_instance(box->calls.next, call_t, link);	415	request = list_get_instance(box->calls.next, call_t, link);
418	list_remove(&request->link);	416	list_remove(&request->link);
419	/* Append request to dispatch queue */	417	/* Append request to dispatch queue */
420	list_append(&request->link, &box->dispatched_calls);	418	list_append(&request->link, &box->dispatched_calls);
421	} else {	419	} else {
422	/* This can happen regularly after ipc_cleanup */	420	/* This can happen regularly after ipc_cleanup */
423	spinlock_unlock(&box->lock);	421	spinlock_unlock(&box->lock);
424	goto restart;	422	goto restart;
425	}	423	}
426	spinlock_unlock(&box->lock);	424	spinlock_unlock(&box->lock);
427	return request;	425	return request;
428	}	426	}
429		427
430	/** Answer all calls from list with EHANGUP answer.	428	/** Answer all calls from list with EHANGUP answer.
431	*	429	*
432	* @param lst Head of the list to be cleaned up.	430	* @param lst Head of the list to be cleaned up.
433	*/	431	*/
434	void ipc_cleanup_call_list(link_t *lst)	432	void ipc_cleanup_call_list(link_t *lst)
435	{	433	{
436	call_t *call;	434	call_t *call;
437		435
438	while (!list_empty(lst)) {	436	while (!list_empty(lst)) {
439	call = list_get_instance(lst->next, call_t, link);	437	call = list_get_instance(lst->next, call_t, link);
440	if (call->buffer)	438	if (call->buffer)
441	free(call->buffer);	439	free(call->buffer);
442	list_remove(&call->link);	440	list_remove(&call->link);
443		441
444	IPC_SET_RETVAL(call->data, EHANGUP);	442	IPC_SET_RETVAL(call->data, EHANGUP);
445	_ipc_answer_free_call(call);	443	_ipc_answer_free_call(call);
446	}	444	}
447	}	445	}
448		446
449	/** Disconnects all phones connected to an answerbox.	447	/** Disconnects all phones connected to an answerbox.
450	*	448	*
451	* @param box Answerbox to disconnect phones from.	449	* @param box Answerbox to disconnect phones from.
452	* @param notify_box If true, the answerbox will get a hangup message for	450	* @param notify_box If true, the answerbox will get a hangup message for
453	* each disconnected phone.	451	* each disconnected phone.
454	*/	452	*/
455	void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)	453	void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box)
456	{	454	{
457	phone_t *phone;	455	phone_t *phone;
458	DEADLOCK_PROBE_INIT(p_phonelck);	456	DEADLOCK_PROBE_INIT(p_phonelck);
459	ipl_t ipl;	457	ipl_t ipl;
460	call_t *call;	458	call_t *call;
461		459
462	call = notify_box ? ipc_call_alloc(0) : NULL;	460	call = notify_box ? ipc_call_alloc(0) : NULL;
463		461
464	/* Disconnect all phones connected to our answerbox */	462	/* Disconnect all phones connected to our answerbox */
465	restart_phones:	463	restart_phones:
466	ipl = interrupts_disable();	464	ipl = interrupts_disable();
467	spinlock_lock(&box->lock);	465	spinlock_lock(&box->lock);
468	while (!list_empty(&box->connected_phones)) {	466	while (!list_empty(&box->connected_phones)) {
469	phone = list_get_instance(box->connected_phones.next,	467	phone = list_get_instance(box->connected_phones.next,
470	phone_t, link);	468	phone_t, link);
471	if (SYNCH_FAILED(mutex_trylock(&phone->lock))) {	469	if (SYNCH_FAILED(mutex_trylock(&phone->lock))) {
472	spinlock_unlock(&box->lock);	470	spinlock_unlock(&box->lock);
473	interrupts_restore(ipl);	471	interrupts_restore(ipl);
474	DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);	472	DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
475	goto restart_phones;	473	goto restart_phones;
476	}	474	}
477		475
478	/* Disconnect phone */	476	/* Disconnect phone */
479	ASSERT(phone->state == IPC_PHONE_CONNECTED);	477	ASSERT(phone->state == IPC_PHONE_CONNECTED);
480		478
481	list_remove(&phone->link);	479	list_remove(&phone->link);
482	phone->state = IPC_PHONE_SLAMMED;	480	phone->state = IPC_PHONE_SLAMMED;
483		481
484	if (notify_box) {	482	if (notify_box) {
485	mutex_unlock(&phone->lock);	483	mutex_unlock(&phone->lock);
486	spinlock_unlock(&box->lock);	484	spinlock_unlock(&box->lock);
487	interrupts_restore(ipl);	485	interrupts_restore(ipl);
488		486
489	/*	487	/*
490	* Send one message to the answerbox for each	488	* Send one message to the answerbox for each
491	* phone. Used to make sure the kbox thread	489	* phone. Used to make sure the kbox thread
492	* wakes up after the last phone has been	490	* wakes up after the last phone has been
493	* disconnected.	491	* disconnected.
494	*/	492	*/
495	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);	493	IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP);
496	call->flags \|= IPC_CALL_DISCARD_ANSWER;	494	call->flags \|= IPC_CALL_DISCARD_ANSWER;
497	_ipc_call(phone, box, call);	495	_ipc_call(phone, box, call);
498		496
499	/* Allocate another call in advance */	497	/* Allocate another call in advance */
500	call = ipc_call_alloc(0);	498	call = ipc_call_alloc(0);

Subversion Repositories HelenOS

(root)/branches/dd/kernel/generic/src/ipc/ipc.c – Rev 4201 → 4296